Motor vehicles such as pickup trucks include a bed for carrying cargo. Tonneau covers are available to cover the cargo bed of a pickup truck. A tonneau cover generally includes a cover, a frame system that supports the cover, and a clamp system that is configured to secure the tonneau cover relative to a rail member configured on the pickup truck bed. While many tonneau cover clamps are useful for their intended purpose, many limitations exist. In some configurations, it is awkward and difficult to manipulate conventional clamp systems between various clamped and unclamped positions. Furthermore, in some instances it is difficult to apply sufficient downward and lateral (outboard or cross-car) tension across the tonneau cover. In addition, it is difficult to secure a tonneau cover in a repeatable fashion using the conventional clamp systems. Thus, while conventional tonneau cover clamp systems work for their intended purpose, there remains a need for improvement in the relevant art.